The complex nature of critical illness often necessitates the use of multiple therapeutic agents, many of which may individually or in combination have the potential to cause renal injury. The use of nephrotoxic drugs has been implicated as a causative factor in up to 25% of all cases of severe acute renal failure in critically ill patients. Acute tubular necrosis is the most common form of renal injury from nephrotoxin exposure, although other types of renal failure may be seen. Given that this is a preventable cause of a potentially devastating complication, a comprehensive strategy should be used to avoid nephrotoxicity in critically ill patients including: accurate estimation of pre-existing renal function using serum creatinine-based glomerular filtration rates, avoidance of nephrotoxins if possible, ongoing monitoring of renal function, and immediate discontinuation of suspected nephrotoxins in the event of renal dysfunction.